/Engine/Plugins/Importers/USDImporter/Source/USDStageEditor/Public/USDStageEditorBlueprintLibrary.h
Creates a new memory-only layer and opens an USD Stage with that layer as its root. Corresponds to the "File -> New" action on the USD Stage Editor menu bar.
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category="USD|Menu Actions") static void FileNew()